Editing Ulcerative colitis (section)

===Laboratory tests===
Blood and stool tests serve primarily to assess disease severity, level of inflammation and rule out causes of infectious colitis.  All individuals with suspected ulcerative colitis should have stool testing to rule out infection.<ref name="Ungaro" />

A [[complete blood count]] may demonstrate anemia, leukocytosis, or thrombocytosis.<ref name="Ungaro" /> Anemia may be caused by inflammation or bleeding. Chronic blood loss may lead to iron deficiency as a cause for anemia, particularly microcytic anemia (small red blood cells), which can be evaluated with a serum [[ferritin]], [[Serum iron|iron]], [[total iron-binding capacity]] and [[transferrin saturation]]. Anemia may be due to a complication of treatment from azathioprine, which can cause low blood counts,<ref>{{cite web |title=Azathioprine Product Information |url=https://www.accessdata.fda.gov/drugsatfda_docs/label/2011/017391s015lbl.pdf |website=Access FDA |publisher=Food and Drug Administration}}</ref> or sulfasalazine, which can result in folate deficiency. Thiopurine metabolites (from azathioprine) and a folate level can help.<ref>{{cite journal | vauthors = Dignass AU, Gasche C, Bettenworth D, Birgegård G, Danese S, Gisbert JP, Gomollon F, Iqbal T, Katsanos K, Koutroubakis I, Magro F, Savoye G, Stein J, Vavricka S | title = European consensus on the diagnosis and management of iron deficiency and anaemia in inflammatory bowel diseases | journal = Journal of Crohn's & Colitis | volume = 9 | issue = 3 | pages = 211–222 | date = March 2015 | pmid = 25518052 | doi = 10.1093/ecco-jcc/jju009 | doi-access = free }}</ref>

UC may cause high levels of inflammation throughout the body, which may be quantified with serum inflammatory markers, such as CRP and ESR.  However, elevated inflammatory markers are not specific for UC and elevations are commonly seen in other conditions, including infection. In addition, inflammatory markers are not uniformly elevated in people with ulcerative colitis.  Twenty five percent of individuals with confirmed inflammation on endoscopic evaluation have a normal CRP level.<ref name="ACG_Guidelines_2019">{{cite journal | vauthors = Rubin DT, Ananthakrishnan AN, Siegel CA, Sauer BG, Long MD | title = ACG Clinical Guideline: Ulcerative Colitis in Adults | journal = The American Journal of Gastroenterology | volume = 114 | issue = 3 | pages = 384–413 | date = March 2019 | pmid = 30840605 | doi = 10.14309/ajg.0000000000000152 | s2cid = 73473272 | doi-access = free }}</ref> [[Serum albumin]] may also be low related to inflammation, in addition to loss of protein in the GI tract associated with bleeding and colitis. [[Vitamin D deficiency|Low serum levels of vitamin D]] are associated with UC, although the significance of this finding is unclear.<ref>{{cite journal | vauthors = Del Pinto R, Pietropaoli D, Chandar AK, Ferri C, Cominelli F | title = Association Between Inflammatory Bowel Disease and Vitamin D Deficiency: A Systematic Review and Meta-analysis | journal = Inflammatory Bowel Diseases | volume = 21 | issue = 11 | pages = 2708–2717 | date = November 2015 | pmid = 26348447 | pmc = 4615394 | doi = 10.1097/MIB.0000000000000546 | doi-access = free }}</ref>

Specific antibody markers may be elevated in ulcerative colitis. Specifically, [[perinuclear antineutrophil cytoplasmic antibodies]] (pANCA) are found in 70 percent of cases of UC.<ref name="ACG_Guidelines_2019" /> Antibodies against ''[[Saccharomyces cerevisiae]]'' may be present, but are more often positive in Crohn's disease compared with ulcerative colitis.  However, due to poor accuracy of these serolologic tests, they are not helpful in the diagnostic evaluation of possible inflammatory bowel disease.<ref name="ACG_Guidelines_2019" /><ref name="Feuerstein_UC" />

Several stool tests may help quantify the extent of inflammation present in the colon and rectum.  [[Fecal calprotectin]] is elevated in inflammatory conditions affecting the colon, and is useful in distinguishing irritable bowel syndrome (noninflammatory) from a flare in inflammatory bowel disease.<ref name="ACG_Guidelines_2019" /> Fecal calprotectin is 88% sensitive and 79% specific for the diagnosis of ulcerative colitis.<ref name="ACG_Guidelines_2019" /> If the fecal calprotectin is low, the likelihood of inflammatory bowel disease are less than 1 percent.<ref name="Ungaro" /> [[Lactoferrin]] is an additional nonspecific marker of intestinal inflammation.<ref>{{cite journal | vauthors = Mosli MH, Zou G, Garg SK, Feagan SG, MacDonald JK, Chande N, Sandborn WJ, Feagan BG | title = C-Reactive Protein, Fecal Calprotectin, and Stool Lactoferrin for Detection of Endoscopic Activity in Symptomatic Inflammatory Bowel Disease Patients: A Systematic Review and Meta-Analysis | journal = The American Journal of Gastroenterology | volume = 110 | issue = 6 | pages = 802–19; quiz 820 | date = June 2015 | pmid = 25964225 | doi = 10.1038/ajg.2015.120 | s2cid = 26111716 }}</ref>